The scene of Friday's tragedy.

Firefighters arrived at the scene and used jacks to lift the boom off Loftus, but were unable to save his life, said FDNY Deputy Chief Joseph Carlsen. The city quickly issued a stop-work order for the site.

“The hydraulics malfunctioned, and the victim was caught between the boom and the flatbed itself,” Carlsen said. “We came on the scene. He was trapped in there.”

A local deliveryman said everything seemed good when he first went past the site where a hotel/residence is under construction.

“They were using the crane on the truck to lift materials up to the second or third floor,” Javier Mendez said. “Everything seemed normal . . . it was fine.”

Loftus wound up in harm’s way when he went to check on a “mechanical failure” with the crane, said Buildings Department spokesman Alexander Schnell.

The problem “caused the boom to collapse on the operator,” he said.

The small crane, known as a knuckle boom, is not regulated or inspected by the city as are the larger cranes, Schnell said.